Telecommunication Rooms Telecom Cabling Telecommunication Rooms

Telecom Cabling Telecommunications rooms (TR) are covered under TIA/EIA 569, these used to be called TCs (telecom closets). On many new construction sites the TRs usually do not have design details included in the blueprints, this means you may have to design on site. Today it is more common to have TR room details than ever before.

Telecom Cabling So far, we have started at the device, attached a patch cord to it, ran that to a wall outlet, then onto some UTP cable. Where does this cable go? The WAO horizontal cable will normally go to some sort of closet.

Telecom Cabling Normally, the horizontal cable ends up at an intermediary closet (IC), Intermediate distribution frame (IDF), or telecommunications room (TR) where it is cross-connected to a backbone system. Todays standards call for Telecom rooms (TRs) and they have very specific requirements.

Telecom Cabling IDF and MDF (main distribution frame) are terms used by the telephony industry in the days of the big monopoly company AT&T. IDFs can still be found in many old buildings and come in many sizes from an enclosure in the wall to a full fledged room. MDFs and IDFs historically only supported voice services, during the 1990s network switches were added to provide network services over CAT 3 cable operating at 10MHz.

Telecom Cabling Eventually as technology evolved so did the standards and the advent of telecom closets replaced IDFs. Today TCs are now telecom rooms (TR) because of their sophistication and the amount of equipment they house to support our high speed data networks. For many corporations and universities this meant finding an existing room to convert to a TR.

Telecom Cabling The TR will support hundreds if not thousands of cables which means an extensive ladder rack system will need to be installed. Rack systems will be discussed in another lecture. Per TIA/EIA 569 there should be a TR on every floor of a multi-story building and should be centrally located so that the distance to any work station does not exceed 295 feet.

Telecom Cabling One of the most important considerations for designing a TR is future proofing (future expansion and growth). Some of the design requirements established from the TIA/EIA 569 standard for TCs are: Dedicated to telecommunications function. Equipment not related to telecommunications shall not be installed, pass through or enter the telecommunications room.

Telecom Cabling Multiple closets on the same floor shall be interconnected by a minimum of one 78mm (trade size 3) conduit, or equivalent pathway. Minimum floor loading (50 lb/ft2). Minimum one closet per floor to house telecommunications equipment/cable terminations and associated cross-connect cable and wire. Located near the center of the area being served.

Telecom Cabling Horizontal pathways shall terminate in the telecommunications room on the same floor as the area served. One wall should have 20mm (0.75 in.) A-C plywood 2.4m (8 ft.) high. Lighting shall be a minimum of 500 lx (50 foot candles) at 1m (3 ft.) above finished floor (AFF). False ceilings shall not be provided.

Telecom Cabling Minimum of two dedicated 120V nominal non-switched duplex electrical outlet receptacles or equivalent, each on separate branch circuits. Additional convenience duplex outlets placed at 1.8m (6 ft.) intervals around perimeter, 150mm (6 in.) above floor. Access to the telecommunications grounding system as specified by ANSI-J-STD-607-A.

Telecom Cabling HVAC requirements to maintain temperature the same as adjacent office area. A positive pressure shall be maintained with a minimum of one air change per hour or per code. These are some of the general requirements for designing a TR, the technician on site will be responsible for the lay out of the equipment and space allocation of the termination fields. You may be asked by an electrician what the power requirements are for this space, refer to the above requirements.

Telecom Cabling Depending on floor space a TC might be located in the center of the space served, here we see the vertical riser system from the entrance facility up to the TCs.

Telecom Cabling The main cross connect (MC) is either a data center or a voice node (PBX room), voice and data services are patched into the building served. On a campus environment one data room may serve several buildings or a 100 buildings, like wise with the PBX room. The network services enter the building in the entrance facility (EF) historically known as the MDF.

Telecom Cabling The EF is also the intermediate cross connect point (IC) to the TC/TR which is the horizontal cross connect point (HC) to the WAO.

Telecom Cabling Lets take a closer look at the inside of a TR. The one of the things that needs to be addressed are the backboards that we will mount termination hardware to. The plywood specified by TIA/EIA 569 is AC (finished on both sides) ¾” fire retardant treated which must also be painted on all sides with two coats of light colored fire resistant paint.

Telecom Cabling The plywood will be used for mounting termination blocks and cross connect fields as well as other low voltage systems such as a PBX or security system. The voice and data equipment will be in close proximity to each other and the ladder rack system will anchor to the plywood.

Telecom Cabling The plywood starts just above the mop board (3”) off of the floor and extends the full 8 feet up.

Telecom Cabling Additional termination blocks can be added below the existing blocks for future growth.

Telecom Cabling Relay racks will be anchored to the floor in front of the termination fields and a ladder rack will “T” off the ladder rack mounted to the plywood.

Telecom Cabling Notice there are three locations where 4” sleeves enter the TR, you will have to consider how you are going to manage and route cable to the designated locations on the backboard and relay racks.

Telecom Cabling Small TR in progress.

Telecom Cabling Here is a TR design.

Telecom Cabling Remember to always consider future proofing in every thing you install, consider this if you fill up the sleeves on one side of the room then you need to add another 4” sleeve for future MACs (moves, adds and changes).